In general, a drum for containing the washed laundry is rotatably installed in a casing of a drying machine. The drying machine dries the laundry by supplying hot air into the drum, and externally discharging wet air, or condensing and discharging moisture of the wet air.
The washed laundry is put into the drum. Since the laundry is washed in a washing machine by using tap water and detergent, calcium of the tap water and a surface active agent of the detergent react with each other and generate insoluble metal soap.
The metal soap remaining in the laundry sticks to fiber remnants or dirties separated from the laundry and absorbs moisture from them, thereby propagating microorganisms. The metal soap may generate floccules causing rot, and may also generate molds causing bad smell. In addition, various germs existing in the air such as Staphyllooccus aureus, Bacillus cereus and Atypical mycobacterium are easily adhered to clothes When many germs remain in the clothes, and if the clothes are not sufficiently dried, the remaining germs propagate themselves, generate unpleasant smell and discolor the clothes.
If sick persons, babies or children having weak immunity wear the clothes in which the germs remain, they may have health problems like a skin disease.